#include "qaes.h"

const quint8 QAesMgr::SBox[] = {
    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
    0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
    0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
    0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
    0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
    0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
    0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
    0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
    0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
    0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
    0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };

const quint8 QAesMgr::RSBox[256] =
{ 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };

const quint8 QAesMgr::Rcon[256] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab };


QByteArray QAesMgr::Crypt(QAesMgr::Aes Level, QAesMgr::Mode Mode, const QByteArray &RawText, const QByteArray &Key, const QByteArray &IV, QAesMgr::Padding Padding)
{
    return QAesMgr(Level, Mode, Padding).Encode(RawText, Key, IV);
}

QByteArray QAesMgr::Decrypt(QAesMgr::Aes Level, QAesMgr::Mode Mode, const QByteArray &RawText, const QByteArray &Key, const QByteArray &IV, QAesMgr::Padding Padding)
{
    return QAesMgr(Level, Mode, Padding).Decode(RawText, Key, IV);
}

QByteArray QAesMgr::ExpandKey(QAesMgr::Aes Level, QAesMgr::Mode Mode, const QByteArray &Key)
{
    return QAesMgr(Level, Mode).expandKey(Key);
}

QByteArray QAesMgr::RemovePadding(const QByteArray &RawText, QAesMgr::Padding Padding)
{
    QByteArray Ret(RawText);
    switch (Padding)
    {
    case Padding::ZERO:
        while (Ret.at(Ret.length() - 1) == 0x00)
            Ret.remove(Ret.length() - 1, 1);
        break;
    case Padding::PKCS7:
        Ret.remove(Ret.length() - Ret.at(Ret.length() - 1), Ret.at(Ret.length() - 1));
        break;
    case Padding::ISO:
        Ret.truncate(Ret.lastIndexOf(0x80));
        break;
    default:
        break;
    }
    return Ret;
}

inline quint8 XTime(quint8 x)
{
    return ((x << 1) ^ (((x >> 7) & 1) * 0x1b));
}

inline quint8 Multiply(quint8 X, quint8 Y)
{
    return (((Y & 1) * X) ^ ((Y >> 1 & 1) * XTime(X)) ^ ((Y >> 2 & 1) * XTime(XTime(X))) ^ ((Y >> 3 & 1) * XTime(XTime(XTime(X)))) ^ ((Y >> 4 & 1) * XTime(XTime(XTime(XTime(X))))));
}


QAesMgr::QAesMgr(Aes Level, Mode Mode, Padding Padding) : MNb(4), MBlocklen(16), MLevel(Level), MMode(Mode), MPadding(Padding)
{
    MState = Q_NULLPTR;

    switch (Level)
    {
    case AES_128:
    {
        AES128 Aes;
        MNk = Aes.Nk;
        MKeyLen = Aes.KeyLen;
        MNr = Aes.Nr;
        MExpandedKey = Aes.ExpandedKey;
    }
    break;
    case AES_192:
    {
        AES192 Aes;
        MNk = Aes.Nk;
        MKeyLen = Aes.KeyLen;
        MNr = Aes.Nr;
        MExpandedKey = Aes.ExpandedKey;
    }
    break;
    case AES_256:
    {
        AES256 Aes;
        MNk = Aes.Nk;
        MKeyLen = Aes.KeyLen;
        MNr = Aes.Nr;
        MExpandedKey = Aes.ExpandedKey;
    }
    break;
    default:
    {
        AES128 Aes;
        MNk = Aes.Nk;
        MKeyLen = Aes.KeyLen;
        MNr = Aes.Nr;
        MExpandedKey = Aes.ExpandedKey;
    }
    break;
    }

}
QByteArray QAesMgr::GetPadding(int CurrSize, int Alignment)
{
    int Size = (Alignment - CurrSize % Alignment) % Alignment;
    if (Size == 0) return QByteArray();
    switch (MPadding)
    {
    case Padding::ZERO:
        return QByteArray(Size, 0x00);
        break;
    case Padding::PKCS7:
        return QByteArray(Size, Size);
        break;
    case Padding::ISO:
        return QByteArray(Size - 1, 0x00).prepend(0x80);
        break;
    default:
        return QByteArray(Size, 0x00);
        break;
    }
    return QByteArray(Size, 0x00);
}

QByteArray QAesMgr::expandKey(const QByteArray &Key)
{
    int i, k;
    quint8 Tempa[4];
    QByteArray RoundKey(Key);

    for (i = MNk; i < MNb * (MNr + 1); i++)
    {
        Tempa[0] = (quint8)RoundKey.at((i - 1) * 4 + 0);
        Tempa[1] = (quint8)RoundKey.at((i - 1) * 4 + 1);
        Tempa[2] = (quint8)RoundKey.at((i - 1) * 4 + 2);
        Tempa[3] = (quint8)RoundKey.at((i - 1) * 4 + 3);

        if (i % MNk == 0)
        {
            k = Tempa[0];
            Tempa[0] = Tempa[1];
            Tempa[1] = Tempa[2];
            Tempa[2] = Tempa[3];
            Tempa[3] = k;

            Tempa[0] = GetSBoxValue(Tempa[0]);
            Tempa[1] = GetSBoxValue(Tempa[1]);
            Tempa[2] = GetSBoxValue(Tempa[2]);
            Tempa[3] = GetSBoxValue(Tempa[3]);

            Tempa[0] = Tempa[0] ^ Rcon[i / MNk];
        }
        if (MLevel == AES_256 && i % MNk == 4)
        {
            Tempa[0] = GetSBoxValue(Tempa[0]);
            Tempa[1] = GetSBoxValue(Tempa[1]);
            Tempa[2] = GetSBoxValue(Tempa[2]);
            Tempa[3] = GetSBoxValue(Tempa[3]);
        }
        RoundKey.insert(i * 4 + 0, (quint8)RoundKey.at((i - MNk) * 4 + 0) ^ Tempa[0]);
        RoundKey.insert(i * 4 + 1, (quint8)RoundKey.at((i - MNk) * 4 + 1) ^ Tempa[1]);
        RoundKey.insert(i * 4 + 2, (quint8)RoundKey.at((i - MNk) * 4 + 2) ^ Tempa[2]);
        RoundKey.insert(i * 4 + 3, (quint8)RoundKey.at((i - MNk) * 4 + 3) ^ Tempa[3]);
    }
    return RoundKey;
}

void QAesMgr::AddRoundKey(const quint8 Round, const QByteArray ExpKey)
{
    QByteArray::iterator Itr = MState->begin();
    for (int i = 0; i < 16; ++i)
        Itr[i] = (quint8)Itr[i] ^ (quint8)ExpKey.at(Round * MNb * 4 + (i / 4) * MNb + (i % 4));
}

void QAesMgr::SubBytes()
{
    QByteArray::iterator Itr = MState->begin();
    for (int i = 0; i < 16; i++)
        Itr[i] = GetSBoxValue((quint8)Itr[i]);
}

void QAesMgr::ShiftRows()
{
    QByteArray::iterator Itr = MState->begin();
    quint8 Temp;

    Temp = (quint8)Itr[1];
    Itr[1] = (quint8)Itr[5];
    Itr[5] = (quint8)Itr[9];
    Itr[9] = (quint8)Itr[13];
    Itr[13] = (quint8)Temp;

    Temp = (quint8)Itr[2];
    Itr[2] = (quint8)Itr[10];
    Itr[10] = (quint8)Temp;
    Temp = (quint8)Itr[6];
    Itr[6] = (quint8)Itr[14];
    Itr[14] = (quint8)Temp;

    Temp = (quint8)Itr[3];
    Itr[3] = (quint8)Itr[15];
    Itr[15] = (quint8)Itr[11];
    Itr[11] = (quint8)Itr[7];
    Itr[7] = (quint8)Temp;
}

void QAesMgr::MixColumns()
{
    QByteArray::iterator Itr = MState->begin();
    quint8 Tmp, Tm, T;

    for (int i = 0; i < 16; i += 4)
    {
        T = (quint8)Itr[i];
        Tmp = (quint8)Itr[i] ^ (quint8)Itr[i + 1] ^ (quint8)Itr[i + 2] ^ (quint8)Itr[i + 3];

        Tm = XTime((quint8)Itr[i] ^ (quint8)Itr[i + 1]);
        Itr[i] = (quint8)Itr[i] ^ (quint8)Tm ^ (quint8)Tmp;

        Tm = XTime((quint8)Itr[i + 1] ^ (quint8)Itr[i + 2]);
        Itr[i + 1] = (quint8)Itr[i + 1] ^ (quint8)Tm ^ (quint8)Tmp;

        Tm = XTime((quint8)Itr[i + 2] ^ (quint8)Itr[i + 3]);
        Itr[i + 2] = (quint8)Itr[i + 2] ^ (quint8)Tm ^ (quint8)Tmp;

        Tm = XTime((quint8)Itr[i + 3] ^ (quint8)T);
        Itr[i + 3] = (quint8)Itr[i + 3] ^ (quint8)Tm ^ (quint8)Tmp;
    }
}

void QAesMgr::InvMixColumns()
{
    QByteArray::iterator Itr = MState->begin();
    quint8 A, B, C, D;
    for (int i = 0; i < 16; i += 4){
        A = (quint8)Itr[i];
        B = (quint8)Itr[i + 1];
        C = (quint8)Itr[i + 2];
        D = (quint8)Itr[i + 3];

        Itr[i] = (quint8)(Multiply(A, 0x0e) ^ Multiply(B, 0x0b) ^ Multiply(C, 0x0d) ^ Multiply(D, 0x09));
        Itr[i + 1] = (quint8)(Multiply(A, 0x09) ^ Multiply(B, 0x0e) ^ Multiply(C, 0x0b) ^ Multiply(D, 0x0d));
        Itr[i + 2] = (quint8)(Multiply(A, 0x0d) ^ Multiply(B, 0x09) ^ Multiply(C, 0x0e) ^ Multiply(D, 0x0b));
        Itr[i + 3] = (quint8)(Multiply(A, 0x0b) ^ Multiply(B, 0x0d) ^ Multiply(C, 0x09) ^ Multiply(D, 0x0e));
    }
}

void QAesMgr::InvSubBytes()
{
    QByteArray::iterator Itr = MState->begin();
    for (int i = 0; i < 16; ++i)
        Itr[i] = GetSBoxInvert((quint8)Itr[i]);
}

void QAesMgr::InvShiftRows()
{
    QByteArray::iterator Itr = MState->begin();
    quint8 Temp;

    Temp = (quint8)Itr[13];
    Itr[13] = (quint8)Itr[9];
    Itr[9] = (quint8)Itr[5];
    Itr[5] = (quint8)Itr[1];
    Itr[1] = (quint8)Temp;

    Temp = (quint8)Itr[10];
    Itr[10] = (quint8)Itr[2];
    Itr[2] = (quint8)Temp;
    Temp = (quint8)Itr[14];
    Itr[14] = (quint8)Itr[6];
    Itr[6] = (quint8)Temp;

    Temp = (quint8)Itr[15];
    Itr[15] = (quint8)Itr[3];
    Itr[3] = (quint8)Itr[7];
    Itr[7] = (quint8)Itr[11];
    Itr[11] = (quint8)Temp;
}

QByteArray QAesMgr::ByteXor(const QByteArray &A, const QByteArray &B)
{
    QByteArray::const_iterator Itr1 = A.begin();
    QByteArray::const_iterator Itr2 = B.begin();
    QByteArray Ret;
    for (int i = 0; i < std::min(A.size(), B.size()); i++)
        Ret.insert(i, Itr1[i] ^ Itr2[i]);

    return Ret;
}

QByteArray QAesMgr::Cipher(const QByteArray &ExpKey, const QByteArray &In)
{
    QByteArray Output(In);
    MState = &Output;

    AddRoundKey(0, ExpKey);

    for (quint8 Round = 1; Round < MNr; ++Round)
    {
        SubBytes();
        ShiftRows();
        MixColumns();
        AddRoundKey(Round, ExpKey);
    }

    SubBytes();
    ShiftRows();
    AddRoundKey(MNr, ExpKey);

    return Output;
}

QByteArray QAesMgr::InvCipher(const QByteArray &ExpKey, const QByteArray &In)
{
    QByteArray Output(In);
    MState = &Output;

    AddRoundKey(MNr, ExpKey);

    for (quint8 Round = MNr - 1; Round > 0; Round--)
    {
        InvShiftRows();
        InvSubBytes();
        AddRoundKey(Round, ExpKey);
        InvMixColumns();
    }

    InvShiftRows();
    InvSubBytes();
    AddRoundKey(0, ExpKey);

    return Output;
}

QByteArray QAesMgr::Encode(const QByteArray &RawText, const QByteArray &Key, const QByteArray &IV)
{
    if (MMode >= CBC && (IV.isNull() || IV.size() != MBlocklen))
        return QByteArray();

    QByteArray Ret;
    QByteArray ExpandedKey = expandKey(Key);
    QByteArray alignedText(RawText);

    alignedText.append(GetPadding(RawText.size(), MBlocklen));

    switch (MMode)
    {
    case ECB:
        for (int i = 0; i < alignedText.size(); i += MBlocklen)
            Ret.append(Cipher(ExpandedKey, alignedText.mid(i, MBlocklen)));
        break;
    case CBC: {
        QByteArray ivTemp(IV);
        for (int i = 0; i < alignedText.size(); i += MBlocklen) {
            alignedText.replace(i, MBlocklen, ByteXor(alignedText.mid(i, MBlocklen), ivTemp));
            Ret.append(Cipher(ExpandedKey, alignedText.mid(i, MBlocklen)));
            ivTemp = Ret.mid(i, MBlocklen);
        }
    }
              break;
    case CFB: {
        Ret.append(ByteXor(alignedText.left(MBlocklen), Cipher(ExpandedKey, IV)));
        for (int i = 0; i < alignedText.size(); i += MBlocklen) {
            if (i + MBlocklen < alignedText.size())
                Ret.append(ByteXor(alignedText.mid(i + MBlocklen, MBlocklen),
                Cipher(ExpandedKey, Ret.mid(i, MBlocklen))));
        }
    }
              break;
    case OFB: {
        QByteArray ofbTemp;
        ofbTemp.append(Cipher(ExpandedKey, IV));
        for (int i = MBlocklen; i < alignedText.size(); i += MBlocklen){
            ofbTemp.append(Cipher(ExpandedKey, ofbTemp.right(MBlocklen)));
        }
        Ret.append(ByteXor(alignedText, ofbTemp));
    }
              break;
    default: break;
    }
    return Ret;
}

QByteArray QAesMgr::Decode(const QByteArray &RawText, const QByteArray &Key, const QByteArray &IV)
{
    if (MMode >= CBC && (IV.isNull() || IV.size() != MBlocklen))
        return QByteArray();

    QByteArray Ret;
    QByteArray ExpandedKey = expandKey(Key);

    switch (MMode)
    {
    case ECB:
        for (int i = 0; i < RawText.size(); i += MBlocklen)
            Ret.append(InvCipher(ExpandedKey, RawText.mid(i, MBlocklen)));
        break;
    case CBC: {
        QByteArray ivTemp(IV);
        for (int i = 0; i < RawText.size(); i += MBlocklen){
            Ret.append(InvCipher(ExpandedKey, RawText.mid(i, MBlocklen)));
            Ret.replace(i, MBlocklen, ByteXor(Ret.mid(i, MBlocklen), ivTemp));
            ivTemp = RawText.mid(i, MBlocklen);
        }
    }
              break;
    case CFB: {
        Ret.append(ByteXor(RawText.mid(0, MBlocklen), Cipher(ExpandedKey, IV)));
        for (int i = 0; i < RawText.size(); i += MBlocklen){
            if (i + MBlocklen < RawText.size()) {
                Ret.append(ByteXor(RawText.mid(i + MBlocklen, MBlocklen),
                    Cipher(ExpandedKey, RawText.mid(i, MBlocklen))));
            }
        }
    }
              break;
    case OFB: {
        QByteArray ofbTemp;
        ofbTemp.append(Cipher(ExpandedKey, IV));
        for (int i = MBlocklen; i < RawText.size(); i += MBlocklen){
            ofbTemp.append(Cipher(ExpandedKey, ofbTemp.right(MBlocklen)));
        }
        Ret.append(ByteXor(RawText, ofbTemp));
    }
              break;
    default:
        break;
    }
    return Ret;
}

QByteArray QAesMgr::removePadding(const QByteArray &RawText)
{
    QByteArray Ret(RawText);
    switch (MPadding)
    {
    case Padding::ZERO:
        while (Ret.at(Ret.length() - 1) == 0x00)
            Ret.remove(Ret.length() - 1, 1);
        break;
    case Padding::PKCS7:
        Ret.remove(Ret.length() - Ret.at(Ret.length() - 1), Ret.at(Ret.length() - 1));
        break;
    case Padding::ISO:
        Ret.truncate(Ret.lastIndexOf(0x80));
        break;
    default:
        break;
    }
    return Ret;
}
